PAT (Advanced Level) 1040. Longest Symmetric String (25) 动态规划

Given a string, you are supposed to output the length of the longest symmetric sub-string. For example, given "Is PAT&TAP symmetric?", the longest symmetric sub-string is "s PAT&TAP s", hence you must output 11.

Input Specification:

Each input file contains one test case which gives a non-empty string of length no more than 1000.

Output Specification:

For each test case, simply print the maximum length in a line.

Sample Input:

Is PAT&TAP symmetric?

Sample Output:

11

最优子结构，子问题重叠。动态规划。

/*2015.7.25cyq*/
#include 
#include 
#include 
using namespace std;

int main(){
	string s;
	getline(cin,s);
	int n=s.size();
	//f[i][j]表示s[i]到s[j]为回文
	vector > f(n,vector(n,false));
	for(int i=0;i=0;i--){
		for(int j=i+1;jmaxlen)
						maxlen=j-i+1;
				}
			}
		}
	}
	cout<